Slashdot is powered by your submissions, so send in your scoop

 


Forgot your password?
Close
typodupeerror
×
Hardware

Electronic Valves For Diesel Engines 168

Posted by Roblimo from the death-to-cams dept.
Anonymous Coward writes: "EETimes describes how electronic valves will replace camshafts in diesel engines starting in 2007. Lower emissions, better performance should follow." This wouldn't be a bad idea in gas engines, either. There's potential here for low emissions, better gas mileage, and greater performance, all at the same time.
This discussion has been archived. No new comments can be posted.

Electronic Valves For Diesel Engines More

Electronic Valves For Diesel Engines

Comments Filter:
  • VW already releases a diesel every year that gets 50-60mpg(golf). This technique would invaluable to them, if patent laws don't prevent them from saving the planet//sarcasim The other new fad this will probally effect heily is the diesel-electric hybrids that every one making for California is forced to produce. This could raise the proformance of the already amazing 80mpg diesel-electric hybrids. --Save the planet--
  • Can this be implemented into cars aswell as trucks.... And will vechicle manafuctures take this technolgy and use it to benifet the consumer in stead of just there bottom line. But sounds like good technolgy to me :] i refuse to drive a car until i can afford a vechicle that doesnt put emiisions that are dangerous to our helth in the air. One in Four children in Australia have asthma ... think what you are doing to kids health before you drive that short distance down the road .

    Burgatronics [burgatronics.net]

  • F1's? (Score:1)

    by Anonymous Coward
    I think Formula one's have been running air or electornic+air timed valves for a long time, should have been in road cars ages ago : )
  • Not only do you have to worry about your car crashing into another car, you now have to worry about the engine itself crashing. I realize that this may lower emissions somewhat, but the crankshaft works so well. Why complicate matters further my incorporating additional electronic circuitry into this fundamental part of the engine. Our cars already contain a huge amount of electronic circuitry, but it is all outside the actual engine. Why start putting electronics inside our engines when the mechanical process in use now works so well.
  • Why can't we ditch this reliance on such stone-age technology as the wheel and axial, burning things, and so forth.
    I want a solid-state car.
    Preferably a solid-state hovercar.
    Preferably not running on WindowsCE.
  • There are some problems with implementing this in cars

    1. They are unsure of running the system at high RPM's(above7200)that cars usually go

    2. The RISC operating system and 24mghz processors need more than 12 volts like cars use now.

    This basicly just means that car manufactures will have to redesign the car as we know it. This just means you will probally be walking or driving a semi for the next ten years

  • Preferably not running on WindowsCE

    Hey this thing is running RISC

  • "...electronic control will enable engines to change valve timing on the fly..."

    Why, it's a run time optimizing just in time combustor!

  • Since it is 1:30 AM and no one else else in America is reading Slashdot, let me try to answer that question.

    ...Hummm, it can't be implemented in cars because they don't have Diesel engines, meaning that the combustion is triggered by spark plugs and not by compression of the hyrdocarbon\oxygen mixture. Since it is mostly the sparks doing the job in a normal automobile engine, the amount\temperture\density of the air doesn't matter as much as it would in a compression based diesel engine. I think.

    The real question I was wondering is when do we get magnetic brakes? Since turntables are powered by magnets, why can't we use magnets to stop car wheels?

    And why don't I know anything? Why am I so ignorant?

  • coool, does that mean all the cars/trucks will be making that funky sound that the cars off the jetsons make when they move? i'm still holding out for the car in a briefcase.
  • A donkey and cart also works well. If the Jones's wankmobile performs better due to (technically unnecessary) complications, the Smiths will engage their free will and individual taste and buy it too :)
    Besides, unnecessary complications that might help ease the damage caused by the predominance of previous unnecessary complications are probably a good thing. :-)

  • This will never happen. Car shops make millions every year adjusting the timing belts that currently drive the camshaft for the valves. If a computer were to control the timing, it would never need adjusting. Not to metion the fact that this would put the companies that make those strobe lights that you use to check the timing out of bussiness.

    On the other hand, this makes herf gunning [slashdot.org] (or worse) a car all the more fun.

    Daniel

  • It will be a long time before these engines will be as reliable as cams and pusher rods. Not to say that is isn't a good approach, but nothing electronic functions very well when it is -40F here, and I have no reason to expect that these engines will be an exception.

    And what exactly happens in a high compression engine when a valve sticks in the open position and the piston comes home? Nothing good!
  • "Our cars already contain a huge amount of electronic circuitry, but it is all outside the actual engine. Why start putting electronics inside our engines when the mechanical process in use now works so well. "

    When was the last time you had a problem with any of those electronic circuits crashing? Mechanical systems fail, electronic ones can too. Your car isn't going to get a BSOD. Embedded microcontrollers are everywhere. Do you fly in planes that are controlled by mechanical systems or electronic ones? Embedded microcontrollers are here to stay.

  • There are some problems with implementing this in cars

    1. They are unsure of running the system at high RPM's(above7200)that cars usually go

    I don't think that'd be a problem for many cars. Unless you really like Honda's and others who really like getting a *lot* of performance out of a smaller displacement block. (Yes, I drive a car that qualifies for that: 97 Integra Type-R 1.8L 195HP 8400RPM redline). Your average joe probably dosen't own car that see's the happy side of 7500RPM without finding out the hard way if it's an interference engine or not...

    2. The RISC operating system and 24mghz processors need more than 12 volts like cars use now.

    It's not voltage, but clean enough power that they will need... You can step up the 12 volts off the car to 110, 5, 12, or what ever you need with a transformer, etc. I'm assuming it's not much of a problem to get it cleaned up enough, as people are running car MP3 players, and what-not already... So, completely redesign them? Nah, just keep the revs down (Boo hiss :)

  • Teh CIA will never allow this (Score:1)

    by Anonymous Coward
    As long as the Grays keep on controlling the Whitehouse
    They will never allow new tech to happen.
    They are here man and they don't want your car to use less gas!!!
  • Allright, we've let the computers control the ignition (and all the stuff inside the car) but fuck me I don't need no virtual cam shaft. Future quote "I'm sorry sir but it looks like your autocam chip fffft-up and your engine is now toast. That will be $200 for the pistons, $600 for the new cam and rods, $300 for the port and polish, $100 for the new cam chip and $2000 for the Microsoft Virtual Cam package. Will that be credit or your first born?

    Cha...ching!!!!!!

    I'll take a 68 mustang fastback any day over any of these new cars!

  • Sadly, it would appear that asthma is effected more by the particles shed from automobile tires than from exhaust. The new high-strength "rubber" makes particles much different from tires 25 years ago. This would explain the recent increases in asthma.

  • The Rock Says... (Score:1)

    by Anonymous Coward
    Diesel engines are a thing of the past and no amount of state of the art technology will ever change that. Let's face it, no serious motorist would ever choose to buy a car with a diesel engine. Diesel engines are just too noisy and don't have the performance of a petrol engine. Petrol engines are the only serious alternative.

    And do we care about the environmental effects? Of course not. Life's too short and we've got to enjoy it while we can. If this means pumping out a few nasty chemicals into the atmosphere while we get our motoring kicks, then that's fair enough. Environmentalists are just a bunch of selfish, moaning old hippies, who profess to care about the planet yet are really just living in constant fear and denial of their own mortality. Their "Save the Planet" slogan can really be translated into "Save My Candy Ass". The planet does not need to be saved! So what if pollution wipes out mankind and life as we know it? Mother Earth will still survive and new forms of life will evolve to replace us.

    The liberal hippies of "Friends of The Earth" and "Greenpeace" are trying to spoil everyone else's enjoyment because they cannot come to terms with the fact that one day they will die, and the human race will become extinct soon after. It is this sort of person who puts the mental into environmental.

  • Renault/Nissan will do that (Unleaded 98) in 2003 (Score:5)

    by Chep ( 25806 ) on Friday April 14, 2000 @11:04PM (#1131349)
    Subject says all ; their prototype "camless" engine is already running. Basically, they use electric actuators instead of the usual cams. And since the engine's electronic already handles fuel injection and air intake... it's just one more parameter.

    Camless engines are routinely used in economy races such as the Shell marathon (run as long as you can, with a single litre of gasoline)...

    What's going to really rock is HDi (or GDi) + Camless + alternatmotor (basically, you replace the smaller alternator + starter combination by a bigger dual-use electric engine/alternator, which allows to give the thermic motor a boost when accelerating, allows stop-and-go when you're stuck on the Périph's monster traffic jams (zero emission, then, and zero noise). Unfortunately, that means switching the car's electric circuit to 48V at least).

    And that's going to be much sooner than 2007 !

    (Besides, Diesel in HDi + Anti-Particle Filter is much more efficient than classic unleaded ; Diesel is easier to refine, and gives a little more energy per mass unit. And direct injection gives the level of control necessary. See whan Peugeot does with Bosch injectors, it's just really amazing).
  • ...why are things being "delayed" until 2007? If the technology is available, why not go for it ASAP, if it will increase performance, decrease pollution and fuel consumption all at once?

    Yet another example of how large corporations become inefficient after they reach a certain "breaking point" size.

    -------
    CAIMLAS

  • Hummm, it can't be implemented in cars because they don't have Diesel engines

    Well, that may be true in USA.

    In Europe there is a looong tradition of cars moved by Diesel engines, mostly turbodiesel with direct injection, which performance is directly comparable (as today almost equal) to gasoline cars, while the engine runs at no more than 3000/4000 RPM (while a gasoline car engine goes up to 7000).

    In Europe, Diesel cars are almost as common as gasoline ones, because of the high costs of gasoline (i.e. in Italy it is $1+ per liter - if a gallon is 3.785 liters, do the math).

    Just for fun, a real alternative to both Diesel and gasoline in the most part of Europe is no less than the... GPL (liquified propane, which is a problem only in underground parkings).

    My 0.02 Euro

  • VW already releases a diesel every year that gets 50-60mpg(golf).

    I have the original version of that diesel engine you speak of. VW calles it the TDI. Turbo Direct Injection. It uses fuel injectors mounted in the combusion chamber wall, removing the intake valve entirely.

    My '96 TDI Passat has an inline 4 at 1.9 liters and is rated at 43 mpg highway. The car is significantly heavier than the Golf, so the difference isn't a big surprise. I've actually gotten up to 47 mpg highway going 55-65 mph. I usually drive about 80-90 mph on highways though, and the mileage drops to about 38 mpg.

    The engine only puts out about 95 horsepower, and redlines at about 4250 rpm. But it does have quite a bit of low-end torque, 150 ft-lbs at about 2000 rpm. Don't get me wrong, its not a fast car by any means. However, it does decently against most other 4 cylinder sedans.

    The later versions of the TDI engine are more fuel efficient and have better performance too.

    I've heard that VW had a 5 cylinder version available in Europe and is working on a V6 version. The TDI has been selling rather well in Europe, as gasoline prices are very high there. In the U.S., there aren't so many.

    The reason that the car runs efficiently is that the direct injection allows the spray of fuel to be directed and controlled. A bowl-shaped cutout in the head causes the fuel to swirl in a heavily-concentrated area in the center of the cylinder while at the edges there is less fuel. The better overall fuel-air ratio is what makes it more efficient.

    The reason that one can't normally achieve the ratio is that the fuel wouldn't ignite if it was evenly distributed at that ratio. The swirling of the fuel allows the ratio at the center to be enough to ignite, while that at the edge brings the overall fuel-air ratio down to more efficent levels.

    I believe Mitsubishi or Toyota is experimenting with direct-injection gasoline engines. Anyone know how their progress is?

  • Could someone with a mechanical background explain the difference between this technology and whatever's in the Hondas and Acuras with "VTEC: Valve Timing Electronically Controlled" splashed on the back? I presume that's not as revolutionary or everyone would be using it... but what's the difference?

  • Honda (Score:1)

    by xer.xes ( 4181 )
    Honda has this will introduce the first car with this sort of technique in 2001. It will be the all new Honda Civic, and the technology is called VTECi (Intelligent Variable Timing Electronically Controlled). Honda introduced the first concept (VTEC) of this on the '89 NSX, and in '91 for the mass market. So nothing really new here!
  • Cam-shafts and electronic valves indeed! My trusty RX-7 needs neither. Rotary engines rule...
  • This is true, Formula 1 race cars have had pnuematic valves for some time now. I think the first time I heard of them was about 5 years ago.

    I have been wanting to do this to my '66 mustang for ages now.......
  • The real question I was wondering is when do we get magnetic brakes? Since turntables are powered by magnets, why can't we use magnets to stop car wheels?

    When we get a useful place to shed all that energy to. Diesel locomotives use regenerative braking, the have an array of huge resistor elements on the top of the beast that turn red-hot when they're engaged.

    The best place to put that energy IMO would be a flywheel. I want a flywheel car! (and think just how hard it would be to roll over! :-)
  • Your car isn't going to get a BSOD.

    Equally annoying things can occur. In the very last stages of my '85 Laser's life the CPU went wonky, and it would turn on the "Check Engine" light and limit RPMs to 3000. In my Spirit trouble detected by the tranny's controller would lock the think in 2nd gear.

  • Re:This will redifine the word "crash" (Score:4)

    by twdorris ( 29395 ) on Friday April 14, 2000 @11:56PM (#1131359)
    > you now have to worry about the engine itself
    > crashing

    Technically, you have to worry about that now. Damn near ever single car manufactured in the last decade has electronic fuel injection and spark control. Embedded microcontrollers take into account their increasingly important role in the overall system when designed. They're written to *not* "crash".

    > but the crankshaft works so well

    Actually, nobody wants to replace the crankshaft, just the camshafts. The problem with a typical camshaft design is that it fixes the cars valve operation profile throughout the entire RPM band. That's extremely inefficient. A standard 16-valve engine running at 7000 RPMs requires a dramatically different camshaft profile than one running at, say, 1500 RPM for maximum efficiency and power. By making valves electronically actuated, you allow the ECU to adjust *everything* automatically for peak operation. Sounds good to me, I just don't wanna be the one to mess up that tight timing code...one good bug would cost a company millions in new motor replacements. :-)

    Thomas Dorris
  • Are they sure we will still have anything to put in our tanks by then? I'd rather see this money go on alternative fuel research.
  • Twaddle indeed. Rotary engines are a very cool concept and get a lot of power in a small space, but they are highly inefficient compared to todays leading petrol engines (I'm talking about things like the Honda VTEC rather than those ugly great V8 engines you love in the states).
    --
  • The difference is: In the VTEC engine there are only two different valve timings. It is not continuously variable as an electronic valve system would be. Why? Because there are no electronics in there. The camshaft has two cam profiles for each valve. Below about 4000rpm one cam profile is used, when the revs get past that, hydraulics push the cam shaft sideways and the other 'high performance' profile is used. Thats why these things are so reliable. Honda offer a 100,000 mile warranty on the engine and they have never had to repair one under warranty.
    --
  • On another note, does anybody really believe that Robin was up and posted this article at 2:10 am on a Friday?

  • The best place to put that energy IMO would be a flywheel. I want a flywheel car! (and think just how hard it would be to roll over! :-)

    Wouldn't it also be rather hard for someone new to it to steer? I know that in aircraft a rotary system makes some very surprising motion possible, but it takes getting used to, and I'm not sure it would even be possible with just a steering wheel.

  • In Truck and Car (used a lot in cars here in europe) applications this might be no bad thing, so long as they get it right, camshafts are a very well developed and understood technology.

    But one of my fathers favorite stories is from when he worked for British Gas (Note for American speakers, here I mean gaseous gas, not petrol). The Thames river in flooded, flooding the gasworks. They got a boat and paddled rounbd the site to the pumphouse, where the big diesel pumps were still chugging along, five feet underwater, keeping the gas pressure up and preventing the pipes flooding, just as they were designed to.

    The point is that the pure mechanical nature of a conventional diesel is a advantage in some situations. Offroaders often like them for their power characteristics, but also because they are very tough compared to petrol units. Similar in boats, you can get away with immersing them in a warm salt mist, that would eat any electronics not immensely shielded, and get away with it.

    EZ
    -'Press Ctrl + Alt + Delete to log on..'
  • but what you need to remember... what's most efficient for corporations isn't what makes the most sense, it's what makes them the most money. If they didn't make as much money off the current mech ways, then that product wouldn't be as efficient (for them) as it could be. It's not like they're missing sales by delaying a release, they're getting more sales... one old model, and one new.
    (and that's as much sense as I can make about big business after a few too many nights of no sleep)


    I'm not ashamed. It's the computer age, nerds are in.
    They're still in, aren't they?
  • The best place to put that energy IMO would be a flywheel. I want a flywheel car! (and think just how hard it would be to roll over! :-)

    Nah, cause a flywheel works on a little known force called momentum. And lord knows, you have to go by the philosophy of "slow and steady wins the race" when you're dealing with momentum.

    You can't just race up to the guy in front of you on the expressway and slam on the brakes like you normally do on the usual USA Interstate Highway System as it exists today.

    Ignore the fact that I nearly got my ass in 3 separate accidents yesterday due to the above phenomena.

    See the below for more info:

    http://www.amasci.com/amateur/traffic/traffic1.h tml

  • You can buy my Mustang! (Score:4)

    by Stephen VanDahm ( 88206 ) on Saturday April 15, 2000 @12:29AM (#1131368)
    I have a silver-blue 1966 Ford Mustang coupe complete with a V8, dual exhausts, and a Pony Interior. My dad and I restored it ourselves when I was in high school. It's in great condition and I can safely say that it is the best looking hard-top Mustang I have ever seen anywhere.

    I love my car dearly. But as much as I love it, we are going to have to get rid of it soon because having a car like that just isn't practical. Sure you can fix it yourself, and the abundance of reproduction parts means that you never have to go through dealers. So it seems that you can save a lot of money this way, right? Wrong. I have never heard of someone being able to save money by driving a vintage car. They are mechanically simple (you can open the hood and see through to the ground), but a consequence of that is that they are VERY POORLY ENGINEERED. If you have options like power steering and an automatic transmission, you'd better be ready to spend a lot of time lying on the garage floor with a wrench in your hand. Any money you save on labor and parts you turn around and spend on more tools and stuff.

    Someone said once that Linux is only free if your time is worthless. You can say the same thing about DIY auto repair. If you work for X dollars per hour, then DIY repair only makes sense if you earn less than the mechanic charges for labor.

    We're probably going to replace the Mustang with a Japanese car, like a Toyota. We have had several rice-burners over the years, and we don't even care that we can't fix them ourselves because they simply never need to be repaired. They were built right from the beginning, so they run forever on nothing but gasoline and regularly scheduled maintenance. We've never had any weird problems with any of the Toyotas we've had, and we put almost 200,000 miles on one of them.

    Oh yeah, did I mention that they get over twice the gas mileage of the Mustang? They don't require the expensive 93 Octane gas either.

    In short, simplicity isn't a virtue when it comes at the expense of functionality and reliability. Furthermore, something as incomprehensibly complex as a modern automobile doesn't have to be unreliable, provided that it was done right from the beginning.

    The complexity of cars will continue to increase dramatically. Gas in South Carolina has doubled in price in two years, and if this continues, people will simply need the fuel efficiency.

    Oh well -- I don't have time to finish, but I hope I've said enough so that my point makes sense.

    Gotta run,

    Steve


    ========
    Stephen C. VanDahm
  • Why wait until 2007? Check out the Honda Insight [honda2000.com] or Toyota Prius (no link b/c of dumb javascript site, but just search for "prius"). Both of these are hybrid gas/electric cars out TODAY that get > 60 mpg for *city driving* (~70 for highway). No chargers or special equipment required. Handles just like a regular car, including acceleration.
    --

  • Bitter and twisted ... (Score:4)

    by threaded ( 89367 ) on Saturday April 15, 2000 @12:35AM (#1131370) Homepage
    Could it be that the manufacturers are not putting this into vehicles for several years because they are waiting for the patent on this invention to time out?

    The idea is quite old now and I actually saw a working system demonstrated at Lotus a good few years before Colin Chapman died. It was used to help design camshaft profiles. You could even use a 'light pen' to pull the curve as the engine operated in real time.

    BTW it definitely was electrohydraulic.

    The patents system is sick, it really needs a overhaul. Here is a system that could have been implemented years ago and saved millions of gallons of fossil fuels from being wasted. What are future generations to think of us.

  • I just bought the 2000 Golf TDI. Very yummy. What's a gas station? VW's had a V6 tdi for some time now. Very popular in Europe. You should head over to www.tdiclub.com [tdiclub.com] if you're interested in all there is to know about the tdi.
  • There's no way I'd drive a car that carried that much angular momentum. In a wreck, really, really annoying things could happen. Not to mention the problems handling the car over unusual terrain (eg bumpy)

  • The planet does not need to be saved! So what if pollution wipes out mankind and life as we know it? Mother Earth will still survive and new forms of life will evolve to replace us.

    Unfortunately, we currently have the capacity to cause serious damage to the planet's ecosystem. If we muck up badly enough, it could take a long, long time for any life to replace us. Unless the cockroaches become significantly more intelligent in less time than seems likely ATM. Besides which, what's wrong with self-preservation? It's what everything's bred for, after all.

  • Rotary engines rule...

    Amen.

    Seem to be getting a lot of interest from some in the aero industry, the AirCar [moller.com] for instance. There is a definate advantage to being able to answer the question 'How many moving parts does your engine have?" with the answer '2'. Compare that to 7 for the simplest four-stroke I have ever met (in a lawnmower). 2 strokes can be nearly as simple I suppose, but the rotary is jsut neat!

    Things get much worse as you add more combustion chambers. Gowd knows how many moving parts in a modern v6/8, and a Honda Vtec, just pray the cambelt never snaps..


    EZ
    -'Press Ctrl + Alt + Delete to log on..'
  • What about the tip seals and lousy gas mileage? They are fun to drive but I wouldn't want to own one.
  • Rotary engines are a very cool concept and get a lot of power in a small space, but they are highly inefficient compared to todays leading petrol engines (I'm talking about things like the Honda VTEC rather than those ugly great V8 engines you love in the states).

    Power to space ratio is one sort of efficiency, but of course you mean fuel efficiency. Not really a fair comparison, since so little engineering effort has been put into them, relatively speaking, and of that which has, fuel efficiency was hardly a focus. Anyway, I obviously didn't buy a sports car for the gas mileage.

    But yeah, granted, none of the *many* rotary autos out there get great mileage, and gas mileage was a salient point of this technology. I still think rotary's a much superior solution. The more so because their superior suitability as hydrogen engines. And anyway, dammit, if I can't be an abrasive technological bigot, what's Slashdot coming to, anyway? ;-)

  • It uses fuel injectors mounted in the combusion chamber wall, removing the intake valve entirely.

    How does the air charge get in??

    I thought that they still had a intake valve, and the TDI merely referred to the clever positioning of the injectors.

    Auto intake valves have been used (no cam, they just open on demand) but have problems because they don't necessarily close when you want, i.e. before ignition...

    TDI systems on a 2-stroke engine are a interesting idea, I know some manufacturer is working on, or has released, such a beast.

    EZ
    -'Press Ctrl + Alt + Delete to log on..'

  • While interesting, what I'm really looking for is: (Score:5)

    by trims ( 10010 ) on Saturday April 15, 2000 @01:02AM (#1131378) Homepage

    ...major improvements in electric engines.

    One of the big bitches of electric cars is (besides battery life) the poor power/weight ratio of the electric engine against the gas (petrol) engine. Also, even more damning, is the relative reliability of the gas engine. What we really need are people putting alot more effort into making a better, lightweight electric engine.

    We already have the parts to build a really good hybrid gas/electric car (which, face it folks, is the only kind of low-emissions vehicle you will see for years). We have the following parts:

    • Electric engine - provides the power to move the car. Also acts as a generator when braking/coasting, thus providing extra power!
    • High-efficiency gas engine - stick in a 300-400 cc motorcycle engine. They generate several kW of power, and can run at optimal efficiency (about 4500RPM) all the time, since you're not using them to directly drive the car. And the parts are readily available, and easy to maintain (and there is a repair infrastructure already in place - your local Kawasaki dealer...) Of course, I'd really like to see us use miniature gas-turbine engines, but I don't expect to see this anytime soon...
    • Zinc-oxide batteries - the so-called "air battery" provides excellent continuous voltage and storage. You may still need a couple of lead-acid around for instantaneous bursts, but probably no more than 2 standard ones.
    • High-speed Flywheels - easily the most efficient and compact way to store energy, a flywheel made of composites can be spun at up to 100,000RPM or more to store energy. And they don't lose energy much (you could leave one spinning overnight and probably only lose a couple hundred RPM, if that). Far more efficient than batteries, these are tre-cool, too.

    The Honda Inspire and the coming competition from Nissan and Toyota are OK, but face it, we need something about the size of a Honda Accord, not a Honda Civic CRX. I can't see any reason (technically) right now why someone doesn't mass-produce a converted Accord. I mean, you can use the exact same design (maybe cheat and use alluminium body panels), just with a new powertrain (with an electric engine, you should probably have a continuously variable transmission, rather than an "automatic", and definately not a "standard") and still get at least 70+ miles/gallon (that is, 30km/l).

    Hell, with the $4k US tax credit for buying a low-emission vehicle, and gas here at $1.85 in the Bay Area, I'd spend $5k more for a converted Accord over a normal one, and still make out like a bandit. So who're the morons in the Marketing Depts at the car manufacturers?

    -Erik

  • What is the story on the next-generation 42V electrical system mentioned in the article?

    I've seen a 28V electrical system in military vehicles, to power radio equipment.

  • right. as usual, I hadn't thought of that... :>
  • It can be implemented and it is going to be implemented RSN. I'm working at BMW and I've seen the prototypes which they've been running for more than a year now. There are still some minor problems, but basically it already works, they're just not going to take it into series development until this kind of engine beats "traditional" engines in all important aspects.
    BTW, high RPM's are, of course, a problem, but none which couldn't be overcome. And, it's not the OS or the processor which need more than 12 volts (who the fuck told you that???), it's the steering of the valves!
    When I saw this article I thought "2007? WTF?". You're gonna be able to buy cars with this kind of engine in about 2 or 3 year's time!!!
  • The BMW engines will use electromagnetic actuation, not the electrohydraulic one this article is talking about. The effect is the same: Exact electronic control of the valve timing.
  • I work at a trucking company in the dispatching department and my parents are truck drivers currently working for the same company, fuel consumption is a great importance in this industry so I think this should be a very good step for the industry.

    however I still do not see the state of California as liking it very much, I remember not too long ago California was discussing making all deisel trucks have a plaque on the side of their trucks saying "Caution: this truck creates fumes that may cause cancer" or something along those lines, they totally ignore the fact that there aremore cars in the state of california at any given time than there are trucks.
    Diesel fuel is more expensive in the state of california because they do not like semi tractor trailers, they place heavy taxes upon diesel fuel making it the most expensive in the country. I think their initial goel is to block all semi's from going into heir state, that would in essence make every thing they sonsume cost a large amount more as the trucks would stop at the border and unload their cargo of 45,000 lbs of beef that californians want for a bar b q on labor day or te 4th of july. only to let several smaller gasonile powered vehicles pick it up and bring it to the warehouses in Los Angeles and Sacramento and other various destinations. Quite frankly it would not bother me very much as I can get reloaded much faster in texas or florida with produce faster and at a higher rate of pay with less over head cost of fuel.

    so if this new engine reduces the amount of "harmful emissions" and makes every one bright and happy again good. better mpg would be nice as it would reduce the overhead and increase my profits just as much.

    but also it will cost more intially if the engine breaks and I have t call around trying to ifind someone that can do some mechanicing on an electronic valve diesel engine which I might find 200-300 miles away instead of hiring the guy in town that knows how to change out a std. camshaft.

    in that respect it will take some time to de virginize the mechanic field and the std diesel engine community as well.

  • I've read that the lotus engineering department was experimenting with a solenoid actuated valve system. But the problem was getting it to work at higher rpm's. It seems that although the systems works, it doesn't work well enough just yet.

    There is some talk about the upcoming use of 'solinoid actuated valve systems' in formula 1 cars, so I guess they are tackling the rpm problem.

    Johan V.
  • I have had my VW Golf TDI for one year now, and I am going in for my 20k service this morning.
    I am really impressed with the mileage. It uses less fuel, needs no tune-ups, is more efficent, and will last twice as long as a gas engine.
    VW is also producing a 150 hp TDI with 250 lb ft. for all the diesel naysayers.
    It really is the best choice for the enviroment.
    ...my car is also Abt/Yokohama/Koni/H&R kitted, which makes it a bit more fun :)
  • The valves in Formula 1 cars arer still operated by a camshaft. The valve return, traditionally done by a simple spring is replaced by a pneumatic system, the so called pneumatic valve return system.

    Johan V.
  • How about 90 mpg in the Europe-only Lupo TDI? With no electric generator. What a great city commuter.
  • You didn't read the article, did you. They're waiting until 2007 because they need testing time, and it has to be approved. Technology can't come overnight you know.
  • ...engine altogether? Come on already! This is 19th century technology here - we can do much better than that!
  • This is a little off topic, but why do car makers think just because they put out an electric or hybrid car they can make it look ugly as ass...

    For example the new Honda hybrid...Why try and make it look all futuristic when it comes out just plain ugly. My friends and I boggle our minds trying to figure out why Honda doesn't convert an Accord or even a Civic over to the hybrid engine. The words out of everyones mouth i talk to about the hybrid car are the same..."It's so damn ugly."

    The hybrid cars aren't the only ones that look just awful, IMHO the new Ford Focus and Toyota Echo are both UGLY. They are designed to be low cost but give me a break... Just keep it nice and simple like a Civic, or even a Metro, why try and make things look all futuristic.

    It almost seems like they have contemporary artists designing cars now instead of engineers.

    just my 1.5 Cents...let the angry replies begin
    -------
    Matt
    "Kick a hole in the speaker, pull the plug and let's jet"
  • yeah, imagine you herf gun someone and all the valves close shut or stop where they are while the car is still rolling, pistons come up and hit valves etc...
  • Actually, electric engines have a pretty good power-to-weight ratio. The problem is that if we put an electric motor in a car that provides the torque (which is constant, unlike the gas engine!) and horsepower that we expect in a vehicle, the damn batteries weigh tons. THAT's our real problem.

    I race R/C cars, and let me tell you, I have an electric dragster that will do better than 85 miles/hour. The electric motor weighs less than a comparable gas engine, but it eats the battery in a couple of runs.

  • I thought this was an interesting look at electric cars [sover.net]. It made me think more about what we need to do to get electric cars to the stage of "It just works" that most people expect.

    Of course what I'm really waiting for is the "Ford Explosion" the new electric-gas hybrid SUV from Ford. Takes up TWO whole lanes on the highway, gets great gas milage (20 mpg), and instantly kills any other cars you hit. :P

  • Re:Beware *mechanical* innovations! (Score:4)

    by garver ( 30881 ) on Saturday April 15, 2000 @03:41AM (#1131394)

    Diesels ain't that great at -40F anyways. You generally need to keep the block warm, either with a heater in the block or by leaving them running.

    So, if the block is already being kept warm, getting the electronics up to a working temperature shouldn't be that difficult.

  • F1 uses pneumatics (for almost a decade, I believe).
    <p>
    The reason why an electromagnetic system is not used in F1 is that current F1 engines rev up to 18000rpm and the current system don't work there yet (I believe BMW has a system that works up to 6000rpm.
  • Allright, they manage to retrofit Otto's invention with some fancy gizmo's to squeeze some more miles out of liquified dinosaurs and trees. Good for them, but this is not what the world (except for those with interests in oil companies) is waiting for I'd say.

    How about getting serious with fuel cells, hydrogen storage and distribution, efficient hydrogen production (not much sense in using an environmentally friendly fuel if that fuel itself is produced using an environmentally unfriendly process)? Several companies here in Europe (Daimler-Benz, Volvo, Fiat) have had fuel-cell powered vehicles in development for quite some time now. The technology seems to work, the range is good, the performance adequate.

    Now THAT is what I call progress.

  • I can report with confidence that my car, which has electronic injection and ignition, has not crashed in the 4 years and 100,000 miles that I have driven it.

    We have already started infiltrating our engines with electronics, and with good results. My midsize sedan gets 30 mpg with all the power I could want. Even back in the stone age days of '96 when a Pentium-166 was a fast computer. In fact, the only things that have needed replaced/failed on my car are pesky mechanical crap: brakes, struts, etc.

    Do not confuse the reliability of your desktop PC with the reliability of embedded systems. They are structured and developed very differently, with an emphasis on reliability.

  • I just read in the last few days about a rumor that Renault is developing an electronic valvetrain for use in 2001. I've been unable to find that article now, otherwise I'd have posted the URL. Renault just bought the Benetton team in the last few weeks, and I'm sure they are keen to find an edge to fend off the other big engine manufacturers involved in the series.

  • Re:This will redifine the word "crash" (Score:1)

    by Anonymous Coward
    But they DO crash, and crash often. I've had to replace them, and they are quite expensive. It might not be such a big deal if they actually improved anything about the car. They don't in my experience. As i said in an earlier message, I do not need a microcontroller to control my tail lights. A simlpe switch, relay, and fuse will do. If one of those breaks, it costs $10 to replace. Instead, I have to replace $150 microcontrollers. Ridiculous.
  • after reading the article (moderators take note), i believe this could new technology applied across the trucking industry could give a serious boost to our economy. these large trucks run over 100,000 miles per year and a new one gets about 7 miles per gallon (loaded) an increase of 10-15% fuel economy could save the transportation industry billions of dollars. this simple change could cause a major econmic boom.
  • i am a medical professional and have done quite a bit of work in the asthma and allergy arena. i've never heard of "rubber" particles being an asthma trigger. do you have any evidence to back your theory? my understanding of physiology would lead me to assume that as heavy as the pariculates would be that they would deposit deeper in the lung and cause more copd (chronic obstructive pulmonary disorder) like symptoms than asthmatic ones.

  • Another big thing with diesels and cold weather is keeping the fuel from gelling up. You must remember to put #1 fuel and/or anti-gel additives in or you will be stuck. Diesels also need a lot of cranking power to start compared to gasoline engines, so the batteries had better work well in the cold weather too.

  • This all great that they are making a better big engines for trucks, but can somebody make a more reliable 2-cycle engine for chainsaws, weedeaters, and the like?

  • And what exactly happens in a high compression engine when a valve sticks in the open position and the piston comes home? Nothing good!

    Which is one reason to make sure that the pistons are dished out where the valves would be. You have the same sort of problem if your timing belt breaks (I have to replace the timing belt in my cars ever 60K miles. The mechanic has said it wouldn't hurt if the belt breaks because the pistons have the necessary indentations, but I don't want to be stranded, so I'll pay the $300 to get them replaced).

  • Other variable valve-timing schemes (Score:3)

    by Botos ( 37607 ) on Saturday April 15, 2000 @04:23AM (#1131405) Homepage
    Honda gives you two cam profiles, but there are some others with even more flexibility. Porsche used a chain they could adjust the tension on to change when the cams engaged. My favorite, though, is the Ferrari V8 system: a shaft with long, tapered cams, so you can push it in or out to get the total range of timings.

    If you've got an interest in engines and can stomach a few equations, I'll go ahead and plug my professor's book: Engines: An Introduction by John L. Lumley.

  • that if your electronics glitch, your engine won't run poorly... it just won't run.

    Then there will be the car running on an MS O/S. Needs to be rebooted at least once a day.


    Gonzo

  • Then how do you charge the battery up? Plug it into a wall outlet when you get to your destination? I know from experience that while a diesel can run without any electricity, the alternator/battery combination is very important because it takes a lot of electricity to start them because they have such a higher compression ratio than gasoline engines. That's one reason why many diesels have two batteries.

  • Hummm, it can't be implemented in cars because they don't have Diesel engines,

    Where have you been? My dad's been driving diesel _cars_ (specifically Oldsmobiles) since the early 80's. His Ciera could get about 40mpg and had over 250K miles on it before he got rid of it. Diesels are available from many of the European car makers, much more so than their US counterparts. I would love to get a TDI Jetta. Given their fuel economy and capacity, it's got something like a 800 mile range. I would only have to fill up once to drive to my parent's house!

  • If you think that riding a tank full of volatile, flammable liquid is bad...

    How about riding a massive wheel rotating at well over 1000 revolutions per second, where any failure of the magnetic bearings results in all that energy being released instantaneously?

    Sure, flywheels are cool and efficient, I might like one in the basement instead of a UPS, but I sure don't want to ride one.

    ----

  • There's not that much of a price difference between gasoline and diesel fuel. In some places in the US, diesel is actually cheaper. Some people don't like diesels because of the noise and they can be a bit sluggish compared to a gasoline engine in the same car (not always the case though). Also diesels can be modified to run on other fuels too. I remember seeing a news blurb on TV about a guy that ran is VW rabbit on vegetable oil he gets from fast food places (his car exhaust smells like french fries). Some cities are experimenting with buses running on soybean oil too.

  • I wouldn't say that. A lot of materials science technology is going into diesel engines. Unlike gasoline engines, the hotter they run the better. Because of this, manufacturers like Caterpillar and Cummins are producing engines with ceramic parts, mainly for construction, agriculture, locomotive, and other similar areas. Because they can run hotter than conventional engines, they need no cooling system, burn cleaner, and are much more efficient. My uncle used to work on some of them and said that after running for about a day, the engines would glow at night because they were so hot. Now this is certainly something that probably won't go into a consumer vehicle sometime soon. But diesels that are available in ordinary passenger cars (such as the TDI Jetta) are more than sufficient for the average person.

    As far as I'm concerned, Greenpeace, Friends of the Earth, EarthFirst, etc. can all go to hell and I wouldn't shed a tear if they were all lost at sea. However, I do think that having clean burning efficient transportation is important. When you are wasting resources (whether it be fuel, paper, metal, etc.) you are wasting money. I'm a cheap bastard at heart, so I always try to recycle and look for efficient items not because I have a 'Save the Earth' complex, but because I don't like spending money. Think about it, once materials separation technology for recycling takes off, cities are going to be making money by strip mining their landfills.

  • I fear the day when cars just become unrepairable once they're much over 10 years old. No one will make the parts for them anymore. Even 3rd party auto parts makers will be hampered by copyrighted firmware in the parts. ANd of course, the mfg wants their car to be replaced after 10 years. Plugs and starters and other parts are easy for a 3rd party to make compatible parts for, but numerous complex and different on every model every year computational components, like HP inkjet cartridges being *only* available from HP, will disappear from the mfg's production line once the car's "projected lifespan" has passed. And cars will suffer the same obsolescence problem as current users of DOS and Win 3.x can well attest to.
  • Well they have already done this. I just read a review on the 2001 Olds Aurora and the only downside was that they didn't have electronic valve control.

    Most high-end engines have this feature. BMW, Mercedes, and Lexus have electronic valve control for their very expenise v8 engines that get incredible horsepower for their size.

    Other features seen on engines now are injectors on each cylinder head, much like a deisel. I have a 2000 GMC with their new V8 5.3 L, 327. Goes fast as hell and still gets around 25mpg. Which is not wonderful but for a half-ton truck with 300 hp... not bad. 5 years ago you would get 15 mpg for 300 hp.

    Actually what amazed me is just how computerized my truck is. If I ran out of coolent a cpu would monitor and control oil and rpm's so i could over 100 km with no coolant. My brakes, 4-wheel disc, have a sensor that makes for even wear on all four discs. Each cylinder is monitored to make sure they have 'optimum burn.' Then of course there is the plug in diagnosis. Which has been around for some time but the information you can get on the entire vehicle is amazing.

  • Ahh, this is my kind of Slasdot article(good 'ol mechanical engineering - my dream career that never came to be).

    I say just retrofit classic cars with these new engines. I'd love to drive a Mini Cooper with an electronic engine, or fuel cell or hybrid. Style and modern tech into 1.
  • That, sir, is one of the cleverest things I've seen in a long time, eliciting my rarely felt, "I wish I'd thought of that."

    (This from a man whose students have described him as a combination professor and standu-up comic :)

    hawk, doffing his hat
  • Are they sure we will still have anything to put in our tanks by then?

    Short answer: YES

    Long answer: There will certainly be gasoline in 7 years. The middle east is sitting on vast reserves of oil, IIRC more than enough to last us 1000 years at current demand. The former Soviet union has huge amounts of petroleum, and you can bet that the big oil companies are investing huge amounts of money into infrastucture and production there, so they can export that oil, too. The US isn't operating at anywhere near it's full potential for oil production; there's no need to, it's cheaper to import petroleum from the middle east than to produce it here. The question is if it will be cheap enough for Americans to keep driving like we do now.
  • "Lots of power" and "high MPG" are mutually exclusive goals. Vehicles that need to be capable of doing *real work* like hauling 40 100lb bags of cement or pulling the boat to the lake, or a house trailer camping, or a horse trailer to the ranch, or a water tank need to be EXEMPTED from stupid smog regs. This exemption must also *not be confined* to "commercial vehicles" or "commercially owned vehicles" as many *individuals* have need to do this too. Maybe a 70MPG Honda Imprevia is good for all your needs, but some of us need more. And it's not just "waaay out in the sticks" either. I live in the Stonehurst area at the top of the San Fernando Valley area which is a low-density ranch area (zoned for horses) smack in the middle of metropolitan Los Angeles. No 70MPG vehicle will carry 3000lbs of feed. Now I hear Calif wants to impose car emmissions requirements on trucks and SUVs? WTF?

  • Re:Bitter and twisted ... (Score:4)

    by hawk ( 1151 ) <hawk@eyry.org> on Saturday April 15, 2000 @05:59AM (#1131423) Journal

    There are *much* simpler explanations than conspiracy theory.

    Basically, they need to make sure the damn thing works before selling it.

    Remember the GM diesel? Basically a buick gas-350 hastily converted and put into production.

    Or the Cadilac 4-6-8? A wonderful idea; 8 cylinders for power, but it could drop a couple out once cruising. Its failure poisoned the well for this technology, and we've gone 20 years without such a system.

    Wait until you get it right. *then* put it on the road.
  • Tip seals? Gas mileage? They'll just write it off as an excuse to get spankin new a ported 3 rotor turbo jobbie dropped in.

    Well... yeah. So? :-)

    It's just like Linux kernel junkies & overclockers...they're too busy futzing with the car & preening over its technical specs to realize they're not actually getting anything done.

    Oh, come now! Overclocking and kernel tweaking are fun. Having fun *is* getting something done. And if you have to drive (a regrettable necessity of most modern folks), you'd might as well have some fun doing it. I can think of no purely utilitarian reason to interest yourself in your car at all.

    What is it with geeks & RX7s? They gotta have the "superior" technology that's barely competitive in the real world with piston engines..

    Untrue, but let's save ourselves the argument and quit here. I think rotaries have great potential for non-sports cars.

    and Im sure the big-peepee styling is a major selling point, too.

    Personally, I wouldn't mind a rotary VW Bug, or some other not-quite-so-macho car. It's the engineering. RX-7s are really good, technically interesting cars.

    Not to mention that the 1st & 2nd gen RX7's are a cheap ticket into sportscar land.

    True

    Pity they couldn't do any better than a Porsche 944 ripoff for the 2nd gen styling though.

    I agree. 1st gens are much cooler.

    I actually wouldn't mind a rotary-powered Miata..that'd be a cute grocery getter to toss around..

    Ahh... the truth comes out! Rotary envy! ;-)

    I've always (ruefully) wondered why they went with a reciprocal engine for the Miata.

  • Re:42V Electrical System? (Score:4)

    by wowbagger ( 69688 ) on Saturday April 15, 2000 @06:10AM (#1131426) Homepage Journal
    The automotive industry is looking into moving to a 42V electrical system because of the number of things in a car that run on electricity rather than mechanical power.


    The problem is what's called i-squared-r: since every wire has a non-zero resistance R, the wire burns off an mount of power proportional to the square of the current in the wire. To deliver the same amount of power to a load, for every doubling of voltage, you halve the current: this is why we have high-tension lines: to deliver a thousand megawatts of power to a city at 100kV takes one thousanth the current that 100V would, so you get one millionth the losses in the wire.


    Now, in automotive use, 12V is really a pain: consider a laptop computer drawing 52 watts of power. At the nominal engine running voltage of 14 volts, you need 4 amps of current to get 52 watts. If your connection to the car's electrical bus has one ohm of resistance (lighter sockets are a lousy interface), you burn off 4 watts of power in the connection (actually, a bit more, since you lose 4 volts across the drop, and now your laptop power supply is trying to get 4.5A to make up for the difference).


    Now, you start getting into steer by wire, electronic valve actuation, ThunderThump 2000 Stereos, maximum-legal output ham radio systems, cell phones, computers, TVs, VCRs, and all of the other things that we are cramming into cars these days, and you are pulling about 2-3kW of power. At 12 volts, this is about 200-300 amps of current. At 42 Volts (three times the nominal run voltage of 14 V), you drop that down to 66-100 amps.


    Of course, you have all the infrastructure of 12V lights and gizmos, all of which have to be replaced. So it isn't going to happen anytime soon.

  • Just like tuneups? (Score:3)

    by hawk ( 1151 ) <hawk@eyry.org> on Saturday April 15, 2000 @06:23AM (#1131427) Journal
    I had my 89 crown victoria tuned in 1990 when I moved from sea level to Vegas--the manual said it was due, and I'd just moved to a higher altitude. That was at 30,000. 30,000 miles later, I took it in again, as the manual said it was due. They charged me about $10 for looking at it, and gave it back, saying it had absolutely no need for a tuneup.

    I've now gone almost 10 years and over 100,000 miles without a tuneup. But there's really nothing left to tuneup on these things--check and see if the spark plugs are fouled, replace any broken spark lines, and make sure the computer hasn't reset itself. My mileage is unchanged from back then, so I have no intention of taking it in any time soon . . .

    It wasn't for a couple of years after they built this one that they started advertising about 100,000 between tuneups . . . and they probably don't need that, either . . .

  • Re:Flywheels are bombs (Score:2)

    by Anonymous Coward

    The danger of a catastrophic flywheel burst is certainly one of the problems to be overcome before flywheel energy storage systems become viable. I have watched safety tests on heavy-duty diesel engine flywheels, in which the wheel is spun on an air turbine in an evacuated pit. They typically burst around 60,000 RPM with bang, fragging into four neat quarters which mangle the six-inch-thick lead blocks lining the pit. k001.

    Flywheels for long-term energy storage are made of layered composites which (one hopes) change the failure mode from fracture to a more mild gradual delamination. I still would not want to ride one though.

  • Firstly, I whole heartedly agree with you that the modern car styles suck.

    I think that because of the battery weights, the older bigger styles of cars may be better targets for diesel-electric hybrids. You have to haul a lot of battery with the current technologies.

    Check out the US Army HumVee project here [evworld.com] and a little more information here [army.mil]. Several minutes of dedicated web searching should turn up more informative links, but hear's the gist I remember from news stories:

    • The original point was to reduce IR and noise signals, in particular to not have a good IR signal for a missile to home in on (but don't those electric motors get really hot ? anyway . . .)
    • The batteries in the bed of the vehicle provided some protection from large anti-vehicle landmines (this might be wrong, I'm remembering it, it wasn't in the linked stories above)
    • It could climb a steeper grade due to the weight of batteries lowering the center of mass
    • Better fuel mileage
    • better acceleration (I was surprised to learn that most electric motors can accelerate a car pretty well, if the car isn't loaded down with batteries to give it a decent range)
    • smaller payload due to all that battery weight
    I would hope to see fleet vehicles like the postal service trucks or delivery trucks like UPS/FedEx start using this technology.

    I have wondered what kind of diesel generator they have. I wonder if you could do better than a piston engine with a small turbine whose rotors or blades were permanent magnents forming the armature of a high-speed generator.

    Anyway, I would not mind having an econoline van with this type of setup on a smaller scale.

  • One in Four children in Australia have asthma ... think what you are doing to kids health before you drive that short distance down the road

    And one in 5 of thouse kids smoke too.

    When I was doing some stat work for a asthma reseach project I found that 90% of all children with asthma were exposed to smoke at least onec a week. The inital surveys answered by their parents showed only about 10%. Thouse that weren't exposed to smoke had problems with either pets, molds, grasses or very rarely foods. I visted a few houses where kids had problems with chemicals. One house had a mould smell so bad I couldn't breath but one of the cleaners the mother used would set off the kids asthma within a few hours. When the kid was taken away from the envioment the cleaner didn't cause a problem.

    So is rubber or diesel a problem for people with asthma? Maybe or maybe not. With any substance you can find someone somewhere that will be effect by it.
  • I've been driving a Jetta TDI for about a year now. Great mileage under normal driving conditions (45-52mpg), excellent range (14.5 gallon tank), performance on par with non-sports cars[1], lower cost for fuel and maintenance and the Jetta design compares well in its class, gas or diesel. They're better for the environment, too - better economy and diesel is easier/cleaner to refine than gas.

    I have a feeling that none of this will matter until someone works to remind the average luser that what they "know" about diesels is wrong. It seems that by far the majority of the American populace thinks that diesels are more expensive, slower and less reliable, none of which is true.

    Right now, the diesel manufacturers seem to be pulling an IBM. They have a better product but seem allergic to actually advertising it. The timing is perfect for a strong ad campaign right now while the US gas prices remain higher than normal ("Wondering why guy who passed you was smiling? His car only needs a fillup once a month and it was cheaper, too")

    [1] In practive I significantly outperform the sportier vehicles as well, but that's a function of the rather bovine drivers that are so common in San Diego: "Whoa! The light! It's green! It's been green for 30 seconds! Ooops, almost stepped on the gas ahead of the rest of the pack. Mustn't get out of line! Listen to that rude driver honking at me just because the light's turning yellow now. He'll only need to run the red a little!"
    (In other words, slower hardware + good software > faster hardware + lousy software)
    __

  • lower cost for fuel
    Not recently.. At one point Diesel was up to US$2 per gallon with regular 87-octane gasoline at about $1.60 per...
    I should mention that this is all relative to what I've seen in San Diego. (This is probably the most appropriate opportunity to trot out YMMV all year! <g>) When I bought gas last week, diesel was at $1.49/gallon vs. $1.69 for the cheapest regular unleaded. This was not the case a month ago, when the diesel was about a nickel a gallon more. I'd say on average it's 10-20 cents a gallon cheaper, modulo the usual sort of market fluctuations.
    __
  • Unfortunately, this whole thread took off on the weekend while I was off-net. I've got enough engine expertise to have short-circuited most of the misinformation going around, but sometimes you just can't be there...
    Perhaps you mean that there is no throttle body valve (or no throttle body) but this is true on all diesel engines.
    What I think this is actually about is the lack of prechambers. A prechamber diesel fires the fuel into a small (hot) space where it is easier to ignite; the partially-burned fuel/air mixture then blows itself out into the cylinder proper. The problem with prechambers is that they have a lot of surface area for their volume and add a lot to heat losses, lowering the efficiency. Direct injection gets rid of this, but causes other difficulties (notably cold starting; a prechamber is much easier to preheat than a whole cylinder).

    I seem to recall that a Golf direct-injection diesel racked up something like 90 MPG in a tour of England some years back. Running at a cruising speed of about 50 MPH and with the lack of throttling losses inherent in the diesel, plus the reduced heat losses of the DI configuration, the only thing that could potentially beat it for efficiency would be a fuel-cell vehicle, and it might take a fuel feed which doesn't require a reformer (which loses efficiency) to get there.
    --

  • There's an Australian company called Orbital which pioneered an air-powered gasoline injector for direct-injection 2-cycle spark engines. Mitsubishi et al. may have drawn some of their inspiration from realms to the south. I know the Japanese don't own the field; GM was testing a 2-cycle engine for a prototype mileage-champ vehicle some time ago. The killer was NOx emissions due to the lean-burn mixture; the engine could not meet EPA specs.
    --
  • Flywheels for long-term energy storage are made of layered composites which (one hopes) change the failure mode from fracture to a more mild gradual delamination.
    Unfortunately, in this context, "gradual" means a fortieth of a second rather than a ten thousandth of a second. And at 60+KRPM, all that's needed to destroy the flywheel is for the vacuum it's spinning in to be compromised. But yah, they do tend to go through bearings--not the solidly mounted ones in laboratories, whose magnetic bearings can hum along nearly forever, but if you put one of these things in a car, you have a fair amount of gyroscopic force to overcome every time you the pitch or roll of the car changes--as in going up a hill. So you have the thing in a gimbal (sp?) system, but if you get in a wreck that knocks the car sideways and thus knocks the 'scope out of its bearings, or torques it out of its bearings, you have a Dramatic Event (tm) to deal with.

    One way to overcome such potential emergencies is to use two counterrotating flywheels. It is much more difficult to extract energy from them (because you have more trouble doing it magnetically through the flywheel housing), but in the event of a detectable failure, you can essentially clamp the two together, resulting in an amazing amount of heat (which can be managed), but no projectiles.

    --

Slashdot Top Deals

Understanding is always the understanding of a smaller problem in relation to a bigger problem. -- P.D. Ouspensky

Close